1. Technical Field
The technical field relates to an imaging apparatus.
2. Description of the Related Art
Recently, digital cameras for converting optical images into electrical signals using imaging elements such as CCD (Charge Coupled Device) and CMOS (Complementary Metal-Oxide Semiconductor) sensors and digitizing and recording the resulting electrical signals, are becoming popular. Digital cameras are easy to handle, and therefore are used widely by photographers with a poor photographing technique and professionals.
Generally, to perform photographing, it is necessary to set photographing parameters related to focus, exposure, color and so on. If photographing parameters are not set appropriately, photographed images become failure images due to unadjusted focus, shake or inappropriate exposure. Then, to prevent failure images from being photographed as quickly as possible, there are a number of devices that install so-called “auto mode” for automatically setting photographing parameters, especially for a photographer with a poor photographing technique. However, auto mode is only an aid for photographing and there are cases where photographing is not possible as intended by the photographer. This is because parameters that must be set vary depending on the photographing technique of the photographer and the environment for photographing and the parameters that must be set in auto mode varies.
Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-124245) proposes a technique of automatically optimizing the parameters to set in auto mode according to the photographer's intention or the condition of use. According to the technique disclosed in Patent Document 1, photographing parameters are automatically optimized according to the photographer's intension and the condition of use by playing back photographed images after photographing, extracting failure images according to the photographer's operation of the failure key and extracting and correcting the auto photographing parameters of failure factors from the extracted failure images. At this point, the auto photographing parameters that have caused the failure factors are extracted automatically or by selecting by the photographer the candidate parameters that are presented. Further, at this point, the parameters or candidate parameters are extracted based on the photographing environment and photographing parameters of failure images (meta data). The photographing environment is determined by each sensor or processing in a microcomputer, and the photographing parameters are set based on the resulting photographing environment.
However, with the above-explained conventional technique, a series of parameter extraction processings are carried out for the first time after photographing. To be more specific, as explained above, after photographing, photographed images are played back, failure images are extracted with the failure key and the photographing parameters of failure factors are extracted from the photographing environment (meta data) and photographing parameters of failure images. Therefore, there is a problem that it is difficult to specify the auto photographing parameters that have caused the failure factors. That is, there are a great number of auto photographing parameters and, even if a table is utilized, a certain limit is imposed upon the setting of the table. Therefore, it is difficult to specify the auto photographing parameters of true failure factors from the photographing environment of failure images and photographing parameters (meta data). It naturally follows that, when the accuracy of specifying the auto photographing parameters that have caused the failure factors decreases, the accuracy of parameters optimization decreases. Further, for example, Patent Document 1 discloses, as the environment for photographing, the degree of focus adjustment (AF evaluation value), AE (shutter speed, aperture opening value, gain, and the degree of flashing a flash lamp), diffuse reflection of outside light (white balance), and discloses, as the photographing parameters, the focus control parameters (AF evaluation value), AE control parameters (shutter speed, aperture opening value, signal processing gain, and the degree of flashing a flash lamp) and white balance control parameters.